Recommendations for Rings and bearings needed

If everything is straight and round it shouldn’t matter what bearings you use. The former is far more important than the latter.

As for rings…for what you are doing I’d run plain cast iron rings. They will take more abuse and still seal and they are easier to get to reseal if you get the tune up off.

The other thing I would suggest is (I’m ASSuming you or your son don’t already have this stuff) at a minimum you need a set of dial calipers. I don’t have an issue with digital calipers but I’m way quicker with a dial. And there are things a digital caliper can do a dial caliper won’t do if you have the money get both.

Then I’d suggest a 0-6 inch micrometer set. Make sure they read in tenths and they come with the appropriate standards.

And, because I’m spending your money (I have all this stuff) I’d suggest a decent dial bore gauge. I think mine goes clear down to .750 and up to 6 inches or something. You can get them relatively cheap.

Then you can measure everything. You can double and triple check the clearances. You’d be surprised at how often humans (even the very best of us) make mistakes. Doo doo occurs. It’s easier to check stuff before it gets together than to get it together and find an issue.